Single electrical stimulus of varying durations and intensities or repetitive stimuli at varying frequencies were applied to a single neuron or to a group of neurons in the cerebral cortex. The responses of the neuron or neurons were recorded. It was found that there are different mechanisms dependent on the interaction of the neurons in the cortex and subcortical nuclei, by which surface epileptiform discharges of different patterns are produced. Furthermore, the neuron, which appears to be an active participant in the generation of surface paroxysmal waves, may become inactive when a surface paroxysmal epileptiform wave appears. BIBLIOGRAPHIC REFERENCE: Li, C.L., Okujava, V.M. and Bak, A.F.: Responses of cerebro-Cortical Neurons to Electrical Stimulation with Particular Reference to Epileptiform Discharges. Exp. Neurol. 55: 173-186, 1977.